Core B, the Animal Core will provide services related to the preparation of all animal models used in the PPG including surgical preparation of the various pig, woodchuck, rat and mouse models and the health maintenance of these chronic animal preparations. Animal husbandry, including normal housing and feeding, will be carried out by the veterinary staff in close coordination with Animal Core personnel. This core supports all projects and supports Core C. The breakdown is as follows: Project 1 will use pigs (20% of Core activity), Project 2 will use pigs and woodchucks (30% of Core activity), Project 3 will use rats, mice and pigs (25% of Core activity), Project 4 will use pigs (20% of Core activity). Core C will require 5% of support from this Core. There are four major functions of Core B. The first component of Core B involves surgical preparation of the animal models, which is required for all of the projects. Secondly, Core B will provide the animal care required for the animal models, including both the care required for maintaining health in chronically instrumented animals and maintenance of the breeding colonies of transgenic mice. The third major function is to provide consultation and assistance where required for performance of the physiologic studies in pigs, woodchucks, rats, and mice, which will be carried out by the individual projects. These include experiments conducted in the conscious state, where possible, and anesthetized when conscious protocols are not possible. The fourth function is administration, since this core services all projects and interacts closely with the other cores, and must meet the regulatory requirements for animal care.